So-called split-bolt connectors of various designs, useful, for example, for the tandem interconnection of conductor ends, are known per se. In this connection reference is made to U.S. Pat. Nos. 2,956,323; 3,298,072; and 2,830,353. With such devices, as well as with so-called U-bolt connectors (in which connection reference is made to U.S. Pat. No. 3,848,953), it is known to utilize a pressure pad member positioned between the bolt head and each associated nut. By this means, conductor ends may be positioned on either or both sides of the pad member; i.e., between it and the contact surfaces associated with the underside of the bolt head and/or the nut by which retention pressure on the conductor ends is affected through cooperative interaction with the bolt threads. It is known to incorporate longitudinally spaced and transversely extending ridges and/or grooves on conductor contacting surfaces in such devices, to promote positive interlock between the various constituent parts and the conductors to be accommodated. Typically, such surfaces may be round in cross-sectional configuration to provide a seat in which the conductors may rest, with the associated ridges and/or grooves being continuous and extending all the way across the groove, substantially normal to the longitudinal axis of the groove.
Such prior art devices have proved to be deficient in their ability to provide the highest degree of retention of a variety of conductor shapes and sizes, particularly as to conductors of relatively small diameter. A source of difficulty has been that when the "lands" or ridges are used which are continuous from one side of the groove to the other, localized high stress, with consequent "notching" across the region of contact between each such land and its associated conductor, can cause strength reductions and breakage proneness which is more severe with smaller-sized conductors.
Accordingly, it is an object of this invention to provide improved retention means for electrical connectors, particularly of the split bolt and U-bolt types.
Another object of this invention is to provide means for achieving the objectives herein set forth which is adapted for use with various conductors of various cross-sectional configurations and/or sizes; particularly a smaller diameter.